Everything you're going to read about and find here has some sort of easy to remember format. For example ... Everything will utilize the number 5. That number isn't random. I use that number because I can assign the item to one of my fingers. The Plus One helps to remember guiding principles, connecting concepts, and other relevant important information. We all know the fivd little bigs represent the questions who, what, when, where and why. Plus One simply refers to the question of 'How'. See how easy that is?
It's all about the who, what, when, where, and why of things. How is determined after all of those have been answered.